Detailed measurements of soot volume fraction, mixture fraction and temperature arereported in a laminar diffusion flame, fuelled by pre-vaporised kerosine and supported ona pressurised WolfhardParker burner. The distributions of these properties in the flameflowfield are simulated computationally and the key parameters in a simplified model of soot formation determined. The model formulation, incorporating the processes of nucleation,surface growth and coagulation, is tailored for subsequent application to turbulent flameprediction.